Primary Type: Formative Assessment
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 55157
Prime or Composite
Students are asked to determine whether each of four given numbers is prime or composite and justify their choices.
Subject(s): Mathematics
Grade Level(s): 4
Intended Audience: Educators
Freely Available: Yes
Keywords: MFAS, prime, composite, factors
Resource Collection: MFAS Formative Assessments
ATTACHMENTS
MFAS_PrimeOrComposite_Worksheet.docx
FORMATIVE ASSESSMENT TASK
Instructions for Implementing the Task
Note: This task may be implemented individually, in small groups, or in a whole-group setting. If the task is given in a whole-group setting, the teacher should ask each
student to explain his or her thinking and strategy.
1. The teacher provides the student with the Prime or Composite worksheet and reads the following to the student:
Determine whether each number below is prime or composite. You may use the white space to show your work. Then circle the correct word describing each number.
2. Encourage the student to justify responses in the white space provided on the worksheet.
TASK RUBRIC
Getting Started
Misconception/Error
The student does not understand the distinction between prime and composite numbers.
Examples of Student Work at this Level
The student:
Does not attempt to find factors of any of the numbers to determine if the numbers are prime or composite.
Lists factors of each number but confuses prime and composite with odd and even.
page 1 of 3 Questions Eliciting Thinking
What do the words prime and composite mean?
Can you list factors of each number? Do you know how to use factors to determine if a number is prime or composite?
Instructional Implications
Provide instruction on the meaning of the terms prime (a whole number greater than one that has only two factors, one and itself) and composite (a whole number greater
than one that has more than two factors). Model for the student how to determine whether a number is prime or composite by investigating its factors. Justify identifying a
number as prime or composite by referring to the number of its factors. For example, explain that seven is prime because it has only two factors (1 and 7). On the other
hand, 15 is not prime since it has more than two factors (1, 3, 5 and 15).
Give the student additional opportunities to determine whether a number is prime or composite, beginning with numbers two through ten.
Making Progress
Misconception/Error
The student makes an error when justifying a response.
Examples of Student Work at this Level
The student understands the distinction between the terms prime and composite. However, the student:
Incorrectly classifies 15 as prime, because he or she neglects the factors three and five.
Correctly identifies 7 and 31 as prime and 15 and 88 as composite but makes an error in his or her explanation. For example, the student says:
Seven is prime because it can only be “multiplied” by one and seven. Seven and 31 each have only one factor.
Confuses the terms composite and prime saying, “88 and 15 are prime, while 7 and 31 are composite.” The student’s explanation. Questions Eliciting Thinking
What are all of the factors of 15? Does 15 have another factor pair in addition to one and 15?
What makes a number prime? What makes a number composite?
Instructional Implications
Model explaining that a number is prime or composite by referring to the number of its factors. For example, explain that seven is prime because it has only two factors (1
and 7). On the other hand, 15 is not prime since it has more than two factors (1, 3, 5, and 15).
Provide additional opportunities to identify numbers as prime or composite and to justify the identifications.
Got It
Misconception/Error
The student provides complete and correct responses to all components of the task.
Examples of Student Work at this Level
page 2 of 3 The student explains that seven and 31 are prime because these numbers only have factors of one and itself. The student explains that 15 and 88 are composite because
both numbers have factors other than one and that number.
Questions Eliciting Thinking
After the number seven, what are the next three prime numbers?
Can you identify all of the factor pairs for the composite number, 64?
Instructional Implications
Challenge the student to identify all prime numbers less than 100 by providing the student with a hundred chart. The student can color prime numbers purple and
composite numbers orange. Be sure the student understands that neither zero nor one is a prime number. Challenge the student to explain why one is not a composite
number.
Encourage the student to find a partner to play the prime or composite game. In this game, the student writes each number one through 100 on index cards. Then the
student shuffles the cards and places them face down. The partners take turns flipping a card and determining if the number is prime or composite. Prime numbers correctly
identified are worth three points, composite numbers correctly identified are worth one point each, and the numbers zero and one are worth five points since they are
neither prime nor composite.
ACCOMMODATIONS & RECOMMENDATIONS
Special Materials Needed:
Prime or Composite worksheet
SOURCE AND ACCESS INFORMATION
Contributed by: MFAS FCRSTEM
Name of Author/Source: MFAS FCRSTEM
District/Organization of Contributor(s): Okaloosa
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
MAFS.4.OA.2.4:
Description
Investigate factors and multiples.
a. Find all factor pairs for a whole number in the range 1–100.
b. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the
range 1–100 is a multiple of a given one­digit number. c. Determine whether a given whole number in the range 1–100 is prime or composite.
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